Bone disease in chronic kidney disease

Summary

Chronic kidney disease can affect the mineral balance in your bones – there are several ways in which these problems are managed and treated.

What is renal bone disease cause by?

People with Chronic Kidney Disease sometimes find their bones get weaker and thinner – becoming painful or breaking more easily – as a result of mineral loss. The most common types of bone disease happen when:

A change occurs in the balance between two important minerals in your body - calcium and phosphate - leading to loss of calcium from your bones.

Four small glands (parathyroid glands), which help to regulate calcium in your body, become too active.

A change occurs in the way your body uses vitamin D, a mineral that is important to healthy bones.

Each of the four types of bone disease affect bones in a different way:

Phosphate is in most foods you eat and whatever is not needed in the body is usually removed by your kidneys. When your kidneys have stopped working normally, phosphate may build up in your blood. Too much phosphate in your blood leads to loss of calcium from your bones, which tends to weaken them. Eating foods that are low in phosphate can help to prevent phosphate from building up in your blood. You may also need to take a medicine called a phosphate binder which helps to stop phosphate from being absorbed from the food you eat

Because phosphate stays in your body when your kidneys are no longer able to remove it, four small glands in your neck (parathyroid glands) become too active. When this happens, calcium is removed from your bones over a long period of time, causing them to weaken. Usually, this problem can be helped by making changes in your dialysis treatments, having a low phosphate diet and taking certain medications such as calcium and vitamin D. Surgery is sometimes necessary to remove some of these glands

Vitamin D is an important vitamin which affects your calcium balance. Normally, vitamin D from the food you eat and vitamin and mineral supplements, is changed by the kidneys into an ‘active’ form that can be used by the body. If your kidneys have failed, they can no longer do this important job. Fortunately, the active form of vitamin D is available as a medicine that can be ordered for you by your doctor if needed. (On the whole, over –the-counter vitamin D supplements should be avoided by people with Kidney Disease. Check with your doctor about the right supplements for you. The amount of vitamin D found in the foods you eat is not a problem.)

Will modifying my diet to help prevent renal bone disease?

By reducing phosphate in your diet, you can help to prevent the amount of phosphate in your blood from becoming too high. Foods high in phosphate include:

Dairy products such as milk and cheese

Dried beans and peas

Nuts and peanut butter

How can renal bone disease be treated?

Your treatment may include one or more of the following:

Reducing phosphate in your diet

Taking a medicine called a phosphate binder

Taking medicine with the active form of vitamin D

Changes in your dialysis treatment

An operation to remove the parathyroid glands

Will a kidney transplant help my bones?

A successful kidney transplant may help your bones to heal from the damage that may have occurred during the time prior to your transplant. However, immunosuppressive medication (corticosteroids) taken by some kidney transplant patients can cause problems.